For example, Patent Documents 1 and 2 disclose a blower used for a conventional vehicle air conditioner.
The blower disclosed in Patent Documents 1 and 2 includes a fan which has a plurality of blades connected by a main shroud, a motor for driving the fan, a scroll casing which has a spiral scroll chamber formed around the fan while accommodating the fan, and a motor casing arranged to face the main shroud while accommodating the motor.
In addition, the main shroud is formed with an annular fan rib protruding toward the motor casing, and the motor casing is formed with an annular motor rib protruding toward the main shroud. Thereby, air flowing through the scroll chamber is suppressed from flowing backward, i.e. flowing upstream of the scroll chamber through a gap between the main shroud and the motor casing.
Furthermore, a portion of ventilation air blown to a vehicle interior is motor-cooling air and is introduced into the motor to cool the motor, and the motor-cooling air after passing through the inside of the motor is returned to the scroll chamber through the gap between the main shroud and the motor casing.
The motor rib has a notch portion formed on a portion near a low-pressure region in the scroll chamber such that inner peripheral and outer peripheral spaces of the motor rib communicate with each other through the notch portion. Thereby, the motor-cooling air is returned to the low-pressure region in the scroll chamber through the notch portion. Here, all terminologies related to pressure used in the present disclosure (e.g., “lower pressure” and “high pressure”) refer to a static pressure.